1. Field
The present invention relates to an organic light emitting display.
2. Description of Related Art
Cathode ray tubes (CRTs) have been used to display images. However, CRTs have the disadvantages of being heavy and large in size. Recently, various flat panel displays (FPDs) have been developed that are capable of reducing the heavier weight and larger volume that are the disadvantages of CRTs. Examples of FPDs include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and organic light emitting displays.
Organic light emitting displays can display images using organic light emitting diodes (OLEDs) that generate light by re-combination of electrons and holes. An organic light emitting display has a high response speed and can be driven with low power consumption.
An organic light emitting display includes pixels positioned at crossing regions of data lines and scan lines, a data driver for supplying data signals to data lines, and a scan driver for supplying scan signals to scan lines.
The scan driver sequentially supplies scan signals to scan lines. The data driver supplies data signals to data lines in synchronization with the scan signals.
The pixels are selected when the scan signals are supplied to the scan lines to receive the data signals from the data lines. At this time, the storage capacitors included in the pixels are charged with voltages corresponding to the data signals, and driving transistors control the amount of current supplied from a first power source to a second power source via organic light emitting diodes (OLED), to correspond to the voltages charged in the storage capacitors.
A method of additionally storing the threshold voltages of the driving transistors in the storage capacitors in order to reduce (or minimize) the effect of variations in the threshold voltages of the driving transistors included in the pixels has been used. A structure in which the driving transistors are coupled to each other in the form of a diode may be added to the pixels. Also, in order to turn on the driving transistors coupled to each other in the form of a diode, a structure may be added to the pixels in which initializing voltages that are lower than data signals are supplied to the gate electrodes of the driving transistors.
In such a case, a plurality of transistors are included in the pixels and a plurality of signal lines are formed in a horizontal direction in order to control the transistors. However, as a display panel is enlarged, the switching speed of the transistors is reduced due to (or by) the signal delay phenomenon of the signal lines formed in the horizontal direction.